Wednesday, November 5, 2008

AL4 Gearbox (Water in Gearbox)

206 AL4 Automatic Transmission Gearbox

It is said that you should becareful when driving over flood or pool of water, esepcially with a automatic transmission Peugeot. 
There is a known risk of water getting into the gearbox (altough not 100% proven, it usually happens due to this reason). As to why and how the water can get into the gearbox, nobody knows the "real" reasons, most people suspect what they called the "breather hole" (which they claimed it's for the gearbox to breathe, letting hot air out?).

However, according to the technical documentation of the AL4 Gearbox, there is not such thing as "breather hole/hose"; I think what they're reffering to is the "Filler Plug", which is use to fill the ATF. But, this "Filler Plug"  should be sealed tight,  so we have no idea of the "real" reason as to why and how the water can get into the gearbox; Currently all are just speculactions or assumptions or the infamous "hear-say".

The Good News? 
It seems most of the current model had been modified to counter this problems (hopefully):

Current AL4 Gearbox with a cap? to cover the "Filler Plug" (or so called "breather hole") to avoid water from going in (Blue cap?)

Symptoms Of Possibility Of Water In The Gearbox:
  • Gear slippage in the morning (start the engine and straight away put on D mode and move the car, had to be in cold conditions e.g. early morning)
  • While in motion/moving, extreme jerking of the car when changing gear (Abnormal hard jerking).
  • Warning lights is on (Sport & Snow mode light is blinking)

If any of this symptoms happen,  its best to get your car check by the SC,  normally a simple ATF check to trace any water in it will be able to find out if the gearbox was infested by water.

In any case, if you ever encounter the "Sport & Snow Mode Blinking" issuel;  do not take the issue lightly. There must be some reason which triggers the warning. This warning could be trigger by various reasons, mainly the ATF over heat or not in good condition (e.g. dirty, water?, etc);
Do not take it lightly,  get it check immediately;  And do not pressure the gearbox before the issue is fix (e.g. Do not REV too high or constant high rev, do not stress your gearbox; Do not drive over 100km/h).
If the service centre ignores the problem due to diagnosis shows no fault, insist them to check properly, cause if it's ATF condition, it's hard to diagnose as it is not yet permanent, it could be some part of the ATF is dirty or having problem, and when the sensors detect it,  it flashes the warning. But when you send to the service centre, there warning might not be there again until the sensors detect it again.

Another personal advice I would give is, change your ATF if the diagnosis cannot detect it and the service centre cannot do anything.


intermilan said...

i can't comment on newer AL4 post 2002, but there is such a thing, that we referred to as "breather hole".

I've seen and touch one, its from my own car AL4 gearbox of course.

the primary function?
to let out excessive ATF oil. in situation where the quantity of ATF oil is deemed as excessive which might be due to overfill or due to abnormal ATF oil pressure in gearbox.

its a failsafe device designed with good intention.

i couldn't verify if its equipped with valve, one-way valve to be more precise, that would only let oil out and never anything else in.

where is it?

its situated somewhere on the top surface of the gearbox body, most probably at the back on the right side as it is quite difficult to reach it. need to remove the after-air-filter-box cold air inlet hose (for 206 1.6 16V) to have any hope of reaching it.

how it look like?
its 'L" shape, dimension circa 25x15mm, black hard plastic. one end is 'plugged" into the gearbox body while the other end sprouting outside.

the most simple adjustment is to add a flexible hose to the latter end (that sprouting outside). this is to 'lengthen' the breather hole and place the extended end high up at secure location to minimise risk of foreign materials to sip into the gearbox (assuming it could enter the g/box via the breather hole).

as to the filler plug, it should be properly tighten every time. usage of water proof materials to ensure water proof it advisable

My206GTi said...


Thanks for sharing your information.

Based on the technical documentation which have the AL4 diagram, we can't find anything such as "Breathe Hole", so it got be just a "name" someone give it?

Based on the definition of the function which you mentioned letting excessive oil, from the technical documentation, it is the Job of the Level and Drain plug.

But if you're talking about the "L" shape with one end connected to the gearbox; if I'm not wrong, based on the technical documentation diagram, you're referring to the "Selector Lever"? I'm not sure if water/foreign material "can" enter through there.
Maybe some workshop willing to do a "TEST"? Hehehe

Anyway, based on the technical documentation diagram, there is only 2 way to enter/exit the gearbox, one to fill the ATF, another to drain; but another point highlighted by bm_dp in the forum sounds very logical too; which is, if water can indeed get in, then the ATF can also get out.
And to add on, based on the pressure and the heat in the gearbox, if there is indeed a "leak" or way for any liquid to exit/enter, I think due to the heat and/or pressure, the fluid should go out instead of going in?
I don't know, I'm no engineer/scientist/etc, just trying to understand and get a more possible accurate reason to the problem/issue.

h.montero said...

This is a great article and a very true fact of the Peugeot 206 AL4.

This is my story: I own a Peugeot 206 2005 1.6 16V Automatic Trans (AL4 Gearbox) I live in Dominican Republic in the middle of the caribbean where storms often occur due to the weather conditions here and water pools in the road are mostly common due to poor maintenance to the drainage system.

Around a month a go on a heavy rainy night I was driving back home when I spooted a pool of water in front of me, I was driving probably around 70 KM/H (45 Miles per hour) and get over the pool of water.. Finally got home, the next morning when i was driving my car to work i suddenly notice that the gears were slipping and knocking hard. I inmmediatly put the car in tiptronic and only drive it in the 2nd shift and drive it back home.

I left the car unused for around 4 days, then found this forum and voila.

I checked under the battery stand and there is Breathing hole from the transmission. I took it to my trusted mechanics with a lot of experience in peugeot and he told met that its indeed the problem and to have a transmission fluid flush. The transmission fluid used by the AL4 is really expensive it cost around 200 USD for around 4 bottles of the fluid and the change itself.

The thing is I didnt took my car for the flush but drove my car in tiptronic for somedays to check if i can get rid of the problem.

After one week of usage. The problem was gone.

And a couple of days ago i got my transmission fluid changed and the car runs smooth now.

I took it back to the mechanic and he made an adaption to the breather hole and put a hose to make the breather hole higher so the water doesnt reach it.

And now on, i think it twice before going over a pool of water.

Thanks guys at My206club!

Eugene said...


Hi.. glad you find out this site useful and glad also that your GB is doing good. thank you for sharing your story. :)

rayzel said...

Hi Eugene,

i had the same problem on my ride as discussed and rectified it by changing the ATF..

But one thing i could not understand is that shouldn't the gearbox be airtight? Yeah the hole was created to let out excessive ATF but why is it allowing water to come in?

I got a lame respond by one KS supervisor " in france, there is no such mini flood or puddle of water" in my mind.. WTF!!!

Is 308 using the the AL4 Gearbox.. if yes i must advise Shahriman to check whether the so called "breather hole" is covered now..

Tyson Talenta said...

Yes there is a "hole" with a rubber 1-inch L-shaped hose attached to the hole. I've seen this on my own AL4 gearbox. It is located somewhere further back from the ATF filler plug.

I have the same sympton of gear slippage in early morning cold. I suspect some water in the AL4 since the car has been driving in a flood before. Planning to replace the ATF.

Adi said...

Hi Guys,

I recently rammed into a pool of water near PPUM on Wednesday, come Friday, me wife complaints of the gear slip after drove the car for a while. The D mode will not engage after driving a while during stoppage at tragic lights. So I suspected the water from the flood encounter found its way in.

Come Saturday, immediately when to KS Cheras Chan Siow Lin, and the horror was confirmed.

The gear fluid looks rather milky grey, where is should have been clear if not mixed with water.

Technician briefed me on what can be done, ranging from flushing the gear box, taking down the whole gear and do an overhaul, or replace the gear box completely.

New gear box cost 20K (nearly fainted), recond cost 13K, potong around 5 K. OMG!!!!!!

Gear overhaul 4K!(with no parts replace) ....Then they tried looking for more water in the airduct of the air filter. Luckily. no water. Engine ok.

Then come to the part they open up a compartment where the 'gear valve sensor' is located....not so sure what's the correct name. Then they showed me a milky residue, but they say it's not too bad. They commended that I brought the car early.

Have to start with the cheapest option, flush with 2 bottles, fill with 2 bottles and and after 1000km, flush again and use 2 more bottles. The whole service cost on Saturday cost around RM 600. Then I have to find the extra RM 300 for another flush after 1000km.

If you have this done at Nasim, they'll use 6 bottles in total at one go.

And yes,there is that 'ventilation hole' at the gear box. Something to do when the gear box get too hot and the ventilation hole does something to cool it (lets air in?). I'm no peugeot expert, correct me if I'm wrong.

One more things about KS, Saturdays are only for regular service...if you bring your car for complaints, lambat habis laaaa.....I somehow got lucky that they attend my car because I called them on Friday and came as the first car on Saturday.

Drove back around 1 pm. Then is going to be another 1000km before the next flush.

Lesson to all: Avoid ramming your 206 into high flood waters. Yes, the same comment from KS about France having no mini floods and all.....

Lajnah Kebajikan Rembau said...

I have my own experiece recently. It happen during election day at Tenang. I was driving From Segamat to Gemas and have to cross flood water of slight above tyre level twice for around twenty meter. Luckily my car manage to pas through the flood area. A few day after that my wife complaint that the gear slip. I sent to French Marque Service centre in Senawang and ask them to check through Peugeot planet. Nothing faulty found. So I ask them to replace the Al4 oil. When they drain out the oil, it totally milky/muddy colour. Mechanic suggested me to change the oil again after 1 week. Unfortunately the slippage stil occurs at high temp. Unfortunately before I manage to change the oil again my wife experience very high knocking after slipage and 'faulty gearbox message come out' Next day I sent for oil change again. I drove from the workshop and unfortunately it happen again. Mechanic suggested me to change the solenoid valve soon with 50-50 guaranty that the problem will solve. after 2 days I sent my car to them again to replace the solenoid valve. In the afternoon mechanic call me informed that negative results.Mech also showed me the photo that all the parts service by them were muddy. Mech said either I have to overhaul or change the gearbox. Then told him, wait first beceuse I don't have budget for it. i drove home to conduct my own test after mech reset the faulty. I use only tiptronic because I can easily control the slippage if i notice it. My last fauty gearbox message come when I drove in auto mode. I told my wife , let me drive the car for afew days if ok then only she can drive it back. This is my wife car. I normally drive my old 405. Luckily after two days in shiftronic no slippage occurs. So I decided to try in auto mode because my wife prefer to drive in auto mode. In thrid day test I use more auto mode tahan shiftronic. Thanks God, no slippage. Today I let mywife to drive the car hoping that the slippage nightmare will not come again. That is my story. Moral of the story do not dare to try your AL4 gearbox drive through flooded area. Aberon.

raj kumar said...

You have shared a good and innovative information, I think every car owner should know about this. This is the essential parts of the cars.Car Gearbox Treatment